If He had given us the Shabbat,and had not brought us before Mount Sinai Dayenu, it would have sufficed!

Ilu natan lanu et hashabbat, v'lo keirvanu lifnei har sinai, Dayenu

אִלּוּ נָתַן לָנוּ אֶת הַשַּׁבָּת וְלֹא קֵרְבָנוּ לִפְנֵי הַר סִינַי דַּיֵּנוּ 


haggadah Section: Tzafun
Source: http://en.wikipedia.org/wiki/Dayenu